1. Field
The following description relates to a backlight driving circuit and a display apparatus using the same, and, as an example, to a backlight driving circuit which uses a light-emitting module of a display as a backlight unit (BLU) to display an image, and a display apparatus using the same.
2. Description of the Related Art
A liquid crystal display (LCD) is currently widely used but does not self-emit light. Therefore, a LCD panel includes a backlight unit (BLU) that projects backlight onto the LCD.
The BLU includes a light-emitting unit that generates backlight and a light guide plate that uniformly transmits backlight, which is emitted from a light-emitting module, to a surface of a display panel. The light-emitting unit includes the light-emitting module, the light-emitting module being disposed to efficiently project the backlight onto the LCD. In addition, the light-emitting unit includes a backlight driving circuit that drives the light-emitting module. For example, instead of a conventional cold cathode fluorescent lamp (CCFL), a light-emitting diode (LED), which has high luminance and a long lifespan, attracts attention as a light-emitting device of the BLU.
If a final output terminal or the light-emitting module short-circuits with ground in the backlight driving circuit, parts of the backlight driving circuit may be damaged by an excessive short-circuit current. Therefore, in order to prevent the damage to the parts of the backlight driving circuit, the short-circuit of the backlight driving circuit is to be sensed to control a current flowing in the backlight driving circuit.
As a method of sensing whether the backlight driving circuit has short-circuited, a high side current sensing method is used to connect a short-circuit sensing resistor to an output terminal of a DCDC converter in series and measure a voltage value of the short-circuit sensing resistor. Here, a voltage value of a flowing current is sensed to sense whether the backlight driving circuit has short-circuited, by using a method of sensing the voltage value of the short-circuit sensing resistor and amplifying the sensed voltage value through an amplifier. However, since the voltage value applied to the short-circuit sensing resistor of the output terminal of the DCDC converter is hundreds of volts, an additional high voltage amplifier is required to lower the voltage value.
In other words, since the high side current sensing method uses the DCDC converter, the short-circuit sensing resistor, and the additional high voltage amplifier, additional cost is incurred.